Coordinated Disclosure Timeline
- 2020-12-22: Report sent to vendor.
- 2020-12-22: Vendor acknowledges report receipt.
- 2021-01-05: Issue resolved.
The docbuild.yml GitHub workflow is vulnerable to unauthorized modification of the base repository or secrets exfiltration from a Pull Request.
nrfconnect/sdk-nrf GitHub repository
The latest changeset 246f5f6 to the date.
Issue: Untrusted code is explicitly checked out and run on a Pull Request from a fork
Workflows triggered on
pull_request_target have read/write tokens for the base repository and the access to secrets. By explicitly checking out and running the build script from a fork the untrusted code is running in an environment that is able to push to the base repository and to access secrets. More details can be found in the article Keeping your GitHub Actions and workflows secure: Preventing pwn requests.
on: pull_request_target: branches: - master ... - name: Install base dependencies working-directory: ncs run: | ... pip3 install -r nrf/scripts/requirements-base.txt ... - name: Build documentation working-directory: ncs run: | export PATH="$HOME/.local/bin:$PATH" mkdir -p _build && cd _build cmake -GNinja ../nrf/doc ninja build-all ...
The vulnerability allows for unauthorized modification of the base repository and secrets exfiltration.
This issue was discovered and reported by GHSL team member @JarLob (Jaroslav Lobačevski).
You can contact the GHSL team at
firstname.lastname@example.org, please include a reference to
GHSL-2020-369 in any communication regarding this issue.